Device for securing an implant to tissue

ABSTRACT

An implant device is provided for implantation within an intervertebral space between adjacent vertebrae comprising an implant body, a rotatable portion and a piercing portion configured to pierce the adjacent vertebra.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/034,249 filed Sep. 23, 2013, which is a continuation of U.S.application Ser. No. 13/035,732 filed Feb. 25, 2011, which is acontinuation-in-part of U.S. patent application Ser. No. 12/324,292,filed Nov. 26, 2008, which, claims the benefit of the filing date ofU.S. Provisional Application 60/990,809, filed Nov. 28, 2007, each ofwhich is hereby incorporated by reference in their entirety herein.

FIELD OF THE INVENTION

The invention relates to implant devices for implantation within anintervertebral space and fixation to the adjacent vertebrae.

BACKGROUND OF THE INVENTION

The spine is the central support column for the human body. It includesa series of vertebrae and intervertebral discs between adjacentvertebrae. The vertebrae are formed of hard bone while theintervertebral discs comprise a comparatively soft annulus and nucleus.The intervertebral discs help to absorb pressure, distribute stress, andkeep adjacent vertebrae from grinding against each other.

A variety of spinal conditions including, for example, trauma,deformity, disease, or other degenerative conditions, may result in aperson experiencing pain or limited physical mobility. This pain andreduced mobility is often attributed to the rupture or degeneration ofthe intervertebral discs resulting in compression of spinal nerve roots.

One manner of treating these conditions is through immobilization andfusion of the injured portion of the spine. In spinal fusion surgery,two or more adjacent vertebrae are initially immobilized relative toeach other and, over time, become fused in a desired spatialrelationship. Often, these procedures require correcting the spacingbetween adjacent vertebrae by implanting an intervertebral implant.

One problem with existing intervertebral implants is that, onceinserted, the implants are explanted from between adjacent vertebrae. Topromote immobilization and fusion of adjacent vertebrae, theintervertebral implant should be designed to provide a substantiallyflush interface with the endplates of the adjacent vertebrae. However,studies have shown that the vertebral endplates of the lumbar spine havevarying degrees of concavity. More specifically, the superior endplatesshow a tendency to be less concave than the inferior endplates.Accordingly, there is a need for implants that resist explantation frombetween the adjacent vertebrae and provide for flush engagement with theinferior and superior endplates.

The present invention may be used to fulfill these, as well as otherneeds and objectives, as will be apparent from the following descriptionof embodiments of the present invention.

SUMMARY OF THE INVENTION

Thus, in accordance with one aspect of the invention, an implant deviceis provided for implantation between adjacent vertebrae. The implantdevice comprises an implant body, a plurality of gripping portions, arotatable portion and a piercing portion. The implant body includes aleading edge and a trailing edge. The gripping portions extend from theimplant body and are configured to engage at least one of the adjacentvertebrae. The rotatable portion of the implant body extends from theleading edge to the trailing edge and defines an axis. The rotatableportion is further configured to be rotatable about the axis when theimplant device is positioned between adjacent vertebrae. The piercingportion of the implant device extends from the implant body and isconfigured to rotate about the axis and rotatably pierce an adjacentvertebra.

According to another aspect of the invention, an implant device isprovided for implantation within an intervertebral device betweenadjacent vertebrae, which comprises an implant body, a plurality ofgripping portions, and a piercing portion. The implant body includes aleading edge and a trailing edge and defines a longitudinal axistherebetween. The gripping portions extend from the implant body and areconfigured to grip at least one of the adjacent vertebrae. The piercingportion is integral with the implant body and extends generally normalto the longitudinal axis. Further, the implant body is configured torotate between adjacent vertebrae so that the piercing portion rotatablypierces one of the adjacent vertebrae.

In another aspect of the invention, a spinal implant is provided forbeing secured to adjacent vertebrae. The spinal implant includes animplant body having teeth to frictionally engage the adjacent vertebrae.The spinal implant further includes a pair of elongate scissor arms.

The scissor arms include opposite end portions, with each opposite endportion having a bone penetrating end configured for piercing thesurface of an adjacent vertebrae. A single pivot member such as a pivotpin pivotably interconnects the pair of scissor arms intermediate theopposite end portions thereof and is connected to the implant body. Thepivot pin allows the scissor arms to pivot between a reduced profileinsertion orientation, in which the bone penetrating ends of the scissorarms do not extend beyond the teeth, to a securing orientation. As eachof the scissor arms are pivoted about the single pivot pin toward thesecuring orientation, one of the bone penetrating ends of each scissorarm penetrates one of the vertebral bodies and the other bonepenetrating end of each scissor arm penetrates the other vertebral body.

In one embodiment, the scissor arms are arranged in the insertionorientation so that one of the opposite end portions of each of thescissor arms are adjacent one another. The adjacent end portions eachinclude a tool engagement portion for being engaged by a tool. Inparticular, the tool engagement portions allow for the tool to pivot thescissor arms about the single pivot member. The scissor arms areconfigured so that as they are pivoted both bone penetrating ends ofeach scissor arm pierce the adjacent vertebral bodies.

In another aspect of the present invention, a spinal implant is providedfor being secured to adjacent vertebrae. The spinal implant includessidewall surfaces for providing low-friction engagement with thevertebral bodies as the implant body is inserted. The implant body isconfigured to be rotatable between the adjacent vertebral bodies to animplanted orientation. A first set of teeth adjacent one side wallsurface and a second set of teeth adjacent the other sidewall surfacefrictionally engage the vertebral bodies with the implant body rotatedto the implanted orientation.

An anchoring member of the spinal implant is fixedly connected to theimplant body adjacent the first set of teeth. The anchoring memberincludes a bone piercing portion extending toward the other sidewallsurface. The bone piercing portion is sized, however, to extend beyondthe first set of teeth to a position generally between the first andsecond sets of teeth. As such, as the spinal implant body is rotatedbetween the adjacent vertebrae so that the second set of teeth engagesthe vertebral body before the first set of teeth, the second set ofteeth will also engage the vertebral body before the bone piercingportion of the anchoring member.

In another aspect of the present invention, a method is provided forsecuring an implant body between adjacent vertebral bodies. The methodincludes inserting an implant body between adjacent vertebral bodies sothat opposite smooth surfaces engage corresponding surfaces of theadjacent vertebral body. Once inserted, the implant body is rotated inthe intervertebral space between the adjacent vertebral bodies. Duringrotation, the teeth of the implant body adjacent the smooth surfaceengage the surfaces of the vertebral bodies. After the teeth engage thesurfaces of the vertebral bodies, the implant body continues to rotateso that anchoring members of the implant body pierce the surfaces of theadjacent vertebral bodies to further secure the implant body to theadjacent vertebral bodies.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an implant device in accordance with oneaspect of the invention showing rotatable portions connected to animplant body rotated so that piercing portions extending beyond upperand lower surfaces of the implant body in the securing orientation;

FIG. 2 is an end view of the trailing edge of the implant device of FIG.1 showing the piercing portions in the securing orientation;

FIG. 3 is a perspective view of the implant device of FIG. 1 with thepiercing portions rotated into the central cavity in an insertionorientation;

FIG. 4 is an end view of the implant device of FIG. 1 showing toolengagement portions along a trailing edge of the implant body;

FIG. 5 is an end view of the implant device of FIG. 1 showing a leadingedge of the implant body;

FIG. 6 is an end view of the implant device of FIG. 1 showing theleading edge of the implant body with one of the securing wall portionsremoved;

FIG. 7 is a side view of the implant device of FIG. 1;

FIG. 8 is a top plan view of the implant device of FIG. 1 showing thepiercing portions rotated into the central cavity with barbs in phantomextending from the piercing portions;

FIG. 9 is a perspective view of an implant device in accordance withanother aspect of the invention showing piercing portions rotated outfrom within a central cavity of an implant body in a securingorientation;

FIG. 10 is an end view of the trailing edge of the implant device ofFIG. 9 showing the piercing portions in the securing orientation;

FIG. 11 is a perspective view of the implant device of FIG. 9 showingthe piercing portions rotated into the central cavity in an insertionorientation;

FIG. 12 is an end view of the implant device of FIG. 9 showing toolengagement portions along a trailing edge of the implant body;

FIG. 13 is an end view of the implant device of FIG. 9 showing a leadingedge of the implant body and a securing pin in phantom connecting theleading edge and a removable securing wall portion;

FIG. 14 is an end view of the implant device of FIG. 9 showing theleading edge of the implant body with the securing wall portion removed;

FIG. 15 is a side view of the implant device of FIG. 9;

FIG. 16 is a top plan view of the implant device of FIG. 9 showing thepiercing portions rotated into the central cavity;

FIG. 17 is a perspective view of an implant device in accordance withanother aspect of the invention showing a piercing portion rotated outfrom within a central cavity of an implant body in a securingorientation;

FIG. 18 is an end view of the trailing edge of the implant device ofFIG. 17 showing the piercing portions in the securing orientation;

FIG. 19 is a perspective view of the implant device of FIG. 17 showingthe piercing portions rotated into the central cavity in an insertionorientation;

FIG. 20 is an end view of the implant device of FIG. 17 showing aleading edge of the implant body with the piercing portions in theinsertion orientation;

FIG. 21 is an exploded perspective view of the implant device of FIG.17;

FIG. 22 is a perspective view of an implant device in accordance withanother aspect of the invention showing the piercing portions rotatedout from within a central cavity of an implant body in a securingorientation;

FIG. 23 is a perspective view of an implant device in accordance withanother aspect of the invention showing the piercing portions rotatedout from within a central cavity of an implant body in a securingorientation;

FIG. 24 is a perspective view of an implant device in accordance withanother aspect of the invention showing piercing portions extend acrossa cavity of the implant body and a securing member in phantom extendingthrough a securing throughbore of one of the piercing portions;

FIG. 25 is a side view of the implant device of FIG. 24 showing thepiercing portions extending from an upper surface and a lower surface ofthe implant body;

FIG. 26 is an end view of the leading edge of the implant device of FIG.24 showing a leading edge of the implant body and a penetrating edge anda blunt edge of the piercing portions extending from the implant body;

FIG. 27 is an end view of the implant device of FIG. 24 showing a toolengagement portion of a trailing edge of the implant body;

FIG. 28 is a top plan view of the implant device of FIG. 24 showing thepiercing portion extending across the central cavity;

FIG. 29 is a perspective view of an implant device in accordance withanother aspect of the invention showing piercing portions extendingacross a central cavity of an implant body;

FIG. 30 is a side view of the implant device of FIG. 29 showing thepiercing portions extending from an upper surface and a lower surface ofthe implant body;

FIG. 31 is a top plan view of the implant device of FIG. 29 showing thepiercing portion extending across the central cavity;

FIG. 32 is a perspective view of a spine;

FIG. 33 is a perspective view of the insertion tool;

FIG. 34 is a top perspective view of an alternative implant device inaccordance with another aspect of the invention showing anchoringmembers extending out from a recess of an implant body in a securingorientation;

FIG. 35 is a bottom perspective view of the implant device of FIG. 34showing the anchoring members in the securing orientation;

FIG. 36 is a front view of the implant device of FIG. 34 in theinsertion orientation showing anchoring members in phantom;

FIG. 36A is a front view of the implant device of FIG. 34 in thesecuring orientation showing a portion of anchoring members in phantom;

FIG. 37 is a side view of the implant device of FIG. 34 in the insertionconfiguration showing the implant body in phantom;

FIG. 37A is a side view of the implant device of FIG. 34 in the securingconfiguration showing the implant body in phantom;

FIG. 38 is a bottom view of the implant device of FIG. 34 in theinsertion configuration;

FIG. 38A is a bottom view of the implant device of FIG. 34 in thesecuring configuration;

FIG. 39 is a perspective view of an implant device in accordance withanother aspect of the invention showing teeth on a body of the implantdevice and cutting fins projecting from the body beyond the teeth;

FIG. 40 is a top view of the implant device of FIG. 39 showing thecutting fins extending across a central cavity of the implant body;

FIG. 41 is a side elevational view of the implant device of FIG. 39showing the curvature of the cutting fins of the implant device;

FIG. 42 is a front end elevational view of the implant device of FIG.39;

FIG. 43 is a back end elevational view of the implant device of FIG. 39;

FIG. 44 is a perspective view of an implant device in accordance withanother aspect of the invention showing teeth on an implant body of theimplant device and anchoring members projecting from the implant bodybeyond the teeth;

FIG. 45 is a side elevational view of the implant device of FIG. 44;

FIG. 46 is a top view of the implant device of FIG. 44 showing bonepenetrating portions of the anchoring members extending across a portionof a central cavity of the implant body;

FIG. 47 is a front end elevational view of the implant device of FIG. 44showing base portions of the anchoring members extending from onesidewall surface of the implant body and a bone penetrating portionextending toward an opposite sidewall surface of the implant body;

FIG. 48 is a back end elevational view of the implant device of FIG. 44;

FIG. 49 is a perspective view of an implant device in accordance withanother aspect of the invention showing teeth on upper and lowersurfaces of an implant body and scissor arms shifted into a cavity ofthe implant body in an insertion orientation thereof showing a tool inphantom engaging tool engagement portions of the scissor arms;

FIG. 50 is a front end elevational view of the implant device of FIG. 49showing a gap in an outer wall of the implant body with the scissor armsin the insertion orientation;

FIG. 51 is a top plan view of the implant device of FIG. 49 in theinsertion orientation showing the scissor arms extending into the gap ofthe outer wall in the insertion orientation;

FIG. 52 is a perspective view of the implant device of FIG. 49 showingthe scissor arms shifted so that bone penetrating ends of the scissorarms extend beyond the teeth of the upper and lower surfaces of theimplant body in a securing orientation;

FIG. 53 is a side elevational view of the implant device of FIG. 49 inthe securing orientation;

FIG. 54 is a perspective view of the scissor arms of the implant deviceof FIG. 49 in the securing orientation showing tool engagement portionsof the scissor arms;

FIG. 55 is a perspective view of an implant device in accordance withanother aspect of the invention showing teeth on upper and lowersurfaces of an implant body and scissor arms shifted so that an elongatebase arm and enlarged opposite end portions of the scissor arms do notextend beyond the upper and lower surfaces of the implant body in aninsertion orientation thereof;

FIG. 56 is a front end elevational view of the implant device of FIG. 55showing a gap in an outer wall of the implant body for receivingenlarged end portions of the scissor arms in the insertion orientation;

FIG. 57 is a top plan view of the implant device of FIG. 55 showing thegaps of the outer wall along either end of the central wall portions forreceiving enlarged end portions of the scissor arms in the insertionorientation;

FIG. 58 is a perspective view of the implant device of FIG. 55 showingthe scissor arms in a securing orientation;

FIG. 59 is a side elevational view of the implant device of FIG. 55 inthe securing orientation;

FIG. 60 is a perspective view of the scissor arms of the implant deviceof FIG. 55 in the securing orientation showing tool engagement portionsof the scissor arms;

FIG. 61 is a perspective view of the scissor arms of the implant deviceof FIG. 55 in the securing orientation showing interlocking splines offacing surfaces of the base arm portions of the scissor arms;

FIG. 62 is a perspective view of an implant device in accordance withanother aspect of the invention showing teeth on a body of the implantdevice with scissor arms extending beyond upper and lower surfaces ofthe implant body in a securing orientation;

FIG. 63 is a front end elevational view of the implant device of FIG. 44showing the implant device in an insertion orientation between adjacentvertebral bodies;

FIG. 64 is a front end elevational view of the implant device of FIG. 44showing the implant device rotated so that the teeth of the implant bodyengage surfaces of the adjacent vertebral bodies;

FIG. 65 is a front end elevational view of the implant device of FIG. 44showing the implant device rotated so that the teeth and bonepenetrating portions of the anchoring members engage the surfaces of theadjacent vertebral bodies; and

FIG. 66 is a front end elevational view of the implant device of FIG. 44showing the implant body in the securing orientation between adjacentvertebral bodies with the teeth engaging the surfaces of the adjacentvertebral bodies and the anchor members having penetrated the adjacentvertebral bodies.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIGS. 1-31 and 34-60, implant devices are shownconfigured in accordance with various aspects of the invention for beingimplanted within the spine 6 between adjacent vertebral bodies 10 andsecured to at least one of those bodies 10. Further contemplatedembodiments include artificial discs, annulus plugs, and other implants,such as those described in U.S. Patent Application Publication No.2006/0129238 to Paltzer, U.S. Patent Application Publication No.2007/0282441 to Stream et al., and U.S. Patent Application PublicationNo. 2008/0103598 to Trudeau et al., which are hereby incorporated intheir entirety herein.

With reference to FIGS. 1-8, the implant device 100 is shown inaccordance with one aspect of the invention. The implant device 100includes an implant body 102, a rotatable portion 140 and a piercingportion 180 extending from the rotatable portion 140. The rotatableportion 140 and piercing portion 180 can be arranged in a compactorientation, as shown in FIG. 3, an extended orientation, as shown inFIG. 1, or an intermediate orientation. The rotatable portion 140 andpiercing portion 180 are configured to provide adequate structuralstrength to the implant device 100 so that adequate torque can beapplied so the piercing portion 180 can penetrate the adjacent vertebralbody 10.

The rotatable portion 140 extends from the leading edge 104 of theimplant body 102 to the trailing edge 106 of the implant body 102 anddefines a longitudinal axis 142. In one embodiment, the rotatableportion 140 extends parallel to one of the upper and lower surfaces 110,112 of the implant body 102. In an alternative embodiment, the rotatableportion 140 extends across the implant body 102 in a direction which isnot parallel to either the upper or lower surfaces 110, 112. As shown inFIGS. 1-8, the rotatable portion 140 preferably extends through athroughbore 146 in the trailing edge 106 and a throughbore 148 in theleading edge 104. The throughbores 146 and 148 are preferably locatedgenerally centrally between the lateral edges 108 of the implant body102, as shown in FIG. 2. Further, the throughbores 146, 148 can belocated along the height 105 of the implant body 102. In one embodiment,as shown in FIGS. 1-4, the throughbores 146, 148 are adjacent either theupper surface 110 or lower surface 112 of the implant body 102.

The rotatable portion 140 and the throughbores 146 and 148 areconfigured to permit rotation of the rotatable portion 140 within thethroughbores 146 and 148. Preferably, the throughbores 146 and 148include a smooth annular surface, as shown in FIGS. 2, 3, and therotatable portion 140 includes corresponding annular surfaces at eitherend. In the illustrated embodiment, the rotatable portion 140 includes atubular shaft which includes an annular surface along its entire length.Other configurations, such as the use of a bearing or bushing betweenthe rotatable portion 140 and throughbores 146 and 148, are contemplatedto ease and enable rotation of the rotatable portion 140.

Preferably, the trailing end 147 of the rotatable portion or shaft 140includes a tool engagement portion 144. The tool engagement portion 144is configured to be engaged by a tool apparatus 1000 to rotate therotatable portion 140 and the piercing portion 180 extending therefromabout the longitudinal axis 142. The rotatable portion 140 and toolengagement portion 144 are configured to deliver sufficient torque tothe piercing portion 180 to permit the piercing portion 180 to rotatablypenetrate the adjacent vertebral body 10. In one embodiment, as shown inFIGS. 1-4, the tool engagement portion 144 includes an X-shaped aperturein the trailing end 147 of the rotatable portion 140.

The rotatable portion 140 and implant body 102 are further configured topermit the rotatable portion 140 to be positioned within the implantbody 102. Various configurations include, for example, a collapsiblerotatable portion 140, an expandable implant body 102, and one or bothof the rotatable portion 140 and implant body 102 comprising more thanone member thereby allowing for disassembly prior to positioning of therotatable portion 140 within the implant body 102 and reassembly uponpositioning of the rotatable portion 140 in the desired location.

As shown in FIGS. 5 and 6, the leading edge 104 of the implant bodyincludes a removable securing wall portion 160. The leading edge 104 andremovable securing wall portion 160 define the throughbore 148.Preferably, the throughbore 148 is defined by a penannular portion 145configured to accept the rotatable portion 140 and a rounded portion 149configured to secure the rotatable portion 140 in the penannular portion145. In a preferred embodiment, the leading edge 104 includes thepenannular portion 145 to permit the rotatable portion 140 to bepositioned within both the throughbore 146 of the trailing edge 106 andthe penannular portion 145 of throughbore 148 before the securing wall160 is secured to the leading edge 104. The removable securing wallportion 160 is configured to be secured onto the leading edge 104 by anyknown means. Preferably, as shown in FIGS. 5,6, the leading edge 104includes securing throughbores 162, and the removable securing wallportion 160 includes corresponding securing throughbores 163, thesecuring throughbores 162, 163 configured to receive a securing member164, such as a pin, therein, to secure the removable securing wallportion 160 to the leading edge 104.

More particularly, the implant body 102 includes two removable wallportions 160 to allow an end of the rotatable portions 140 to beremovably captured within the throughbore 148 of the trailing edge 106of the implant body 102. The other end of the rotatable portions 140 canthen be received in a rounded pennanular portion 145 of the leading edge104. A removable wall portion 160 the can then be secured to the leadingedge 104 of the implant body 102. As shown in FIGS. 5 and 6, theremovable wall portion 160 includes a rounded edge 149 configured tocooperate with the rounded portion 145 of the leading edge 104 toprovide a rounded opening 148 for the end of the shaft or rotatableportion 140.

The piercing portion 180 includes a proximal base portion 182, whichextends from the rotatable portion 140, and a distal end portion 186. Inone embodiment, the proximal portion 182 is integral with the rotatableportion 140. In an alternative embodiment, the proximal portion 182 issecured to the rotatable portion 140 by any known means, such as, forexample, a screw, an interlocking mechanism of the proximal portion 182and the rotatable portion 140, or by an adhesive. Preferably, the distalend portion 186 includes a tapered end portion 188 to ease thepenetration of the distal end portion 186 of the piercing portion 180into the vertebral body 10.

In the insertion orientation, the piercing portion 180 is located withina central cavity 122 of the implant body 102, which extends from theupper surface 110 of the implant body 102 to the lower surface 112 ofthe implant body 102, and from the leading edge 104 to the trailing edge106. More particularly, in the insertion orientation, as shown in FIGS.3-7, the piercing portions 180 do not extend beyond gripping members 118or teeth of the upper and lower surfaces 110 and 112 of the implant body102, and are confined between the leading edge 104, trailing edge 106and lateral walls 108 of the implant body 102. The central cavity 122can extend from one lateral edge 108 to the other lateral edge 108.Referring to FIG. 8, the central cavity 122 extends from one lateraledge 108 to a central support portion 120 in the form of an internalwall. More particularly, the central cavity 122, extending betweenlateral edges 108, includes a central support portion or internal wall120 bisecting the central cavity 122. The central support portion orinternal wall 120 extends from the leading edge 104 to the trailing edge106 and is generally intermediate the lateral edges 108. Preferably, thecentral support portion or internal wall 120 extends from the uppersurface 110 of the implant body 102 to the lower surface 112 of theimplant body 102 and is configured to engage and support the adjacentvertebral bodies 10.

In the securing orientation, the piercing portion 180 extends away fromone of the upper and lower surfaces 110, 112 of the implant body 102.The piercing portion 180 is configured to extend above the upper surface110 or lower surface 112 a distance sufficient to secure the implantbody 102 to the vertebral body 10 without compromising the integrity ofthe vertebral body 10. More particularly, the piercing portion 180 isconfigured so that sufficient bone structure remains intact between thetapered end portion 188 and the vertebral surfaces so that the bonestructure is not compromised during normal loading or flexion of thespine as described hereinafter.

As the rotating portion 140 and piercing portion 180 are rotated betweenadjacent vertebral bodies 10, the piercing portion 180 extends, forexample, above the upper surface 110, out of the central cavity 122toward the adjacent vertebral body 10 and, as it does so, penetrates thevertebral body 10. As the piercing portion 180 rotatably penetrates thevertebral body 10, at least one of the implant body 102 and thepenetrated vertebral body 10 are urged toward the other until,preferably, the upper surface 110 firmly engages the vertebral body 10.Similarly, as the rotatable portions or shafts 140 are rotated so thatpiercing portions extend beyond the lower surface 112, the piercingportions 180 penetrate the adjacent vertebral body 10. As the vertebralbody is penetrated by the piercing portions 180, at least one of theimplant body 102 and the penetrated vertebral body 10 are urged towardthe other until the lower surface 112 of the implant body 102 firmlyengages the vertebral body.

As shown, the implant device 100 includes one piercing portion 180extending from one rotatable portion 140. Preferably, the implant device100 includes at least two piercing portions 180 extending from arotatable portion 140, the piercing portions 180 preferably extending inparallel from the rotatable portion 140. In a further preferableembodiment, and as shown in FIGS. 1-4, the implant device 100 includesat least two rotatable portions 140, with one or more piercing portionsextending from each rotatable portion 140. In another embodiment, theimplant device 100 includes two rotatable portions 140 withcorresponding piercing portions 180 configured to extend beyond one ofthe upper and lower surfaces 110, 112 of the implant body 102. In apreferable embodiment, the implant device 100 includes at least tworotatable portions 140 with corresponding piercing portions 180, atleast one rotatable portion 140 with corresponding piercing portions 180configured to extend from each of the upper and lower surfaces 110, 112of the implant body 102.

As shown in FIGS. 1, 3, 8, the rotatable portions 140 and piercingportions 180 are configured to not interfere with one another in theinsertion orientation or the securing orientation. In particular, thepiercing portions 140 can be positioned within the central cavity 122with the piercing portions 180 staggered along the longitudinal axis 142of the rotatable portions 140 so that all of the piercing portions 180can be disposed within the central cavity 122 in the insertionorientation, preferably with the piercing portions 180 positionedgenerally between the upper and lower surfaces 110, 112 of the implantbody 102 to assist in insertion of the implant body 102 between adjacentvertebral bodies 10.

The configuration of the piercing portion 180 is dependent on multiplevariables and is coordinated with multiple structural features of theimplant device including, for example, the width, depth and height ofthe central cavity 122, the location of the rotatable members 140 andcorresponding throughbores 146, 148 within the central cavity 122, andthe number of rotatable members 140 and piercing portions 180 of theimplant device 100. Additional variables include the shape, length,width and depth of the piercing portions 180 and the direction in whichthe piercing portions 180 extend. In particular, repositioning therotatable members 140 and throughbores 146, 148 along the height andwidth of the central cavity 122 can be used to accommodate varyingpiercing portion 180 configurations including, for example, differencesin shape, length, depth, width, and direction in which the piercingportions 180 extend.

Additionally, the particular shape of the piercing portion 180 candepend on factors such as the density of the bone to be penetrated, thedegree of compression required between the device and the bone, thestatic and dynamic loading on the implant and bone, as well as thestrength of the materials used.

As shown in FIGS. 1, 2, the piercing portions 180 extend generally awayfrom the nearest lateral edge 108 and toward the center of the implantbody 102. Alternative embodiments include, for example, piercingportions 180 extending away from the center of the implant body 102 (asshown in FIGS. 9, 10), all the piercing portions 180 extending in thesame direction, or the piercing portions 180 extending in a plurality ofdirections. Preferably, the piercing portions 180 extend in at least twodifferent directions to provide additional stability in securing theimplant device 100 to the adjacent vertebrae. In particular, havingpiercing portions 180 extending in at least two different and preferablygenerally opposite directions toward each other allows the implant body102 to be secured to the adjacent vertebral body 10 without urging thevertebral body 10 in one of these directions, thereby avoiding potentialdamage to the spine and allowing the implant device 100 to be secured inthe desired location.

In a preferred embodiment, as shown in FIGS. 1-9, the rotatable portions140 are positioned adjacent the upper and lower surfaces 110, 112 andtoward the lateral edges 108 of the implant body 102. By positioning therotatable portions 140 away from the center of the implant body 102, theimplant device 100 engages the vertebral bodies at four distinct, spacedlocations, providing for a more secure engagement which does not requireadditional securing methods, such as a pedicle screw or lumbar plate,thereby simplifying the process of securing the vertebral bodies 10 withan implant device 100.

The configuration of the piercing portion 180 is not limited by theexamples shown in FIGS. 1-31 and 34-60. It is contemplated that thepiercing portion 180 can have any configuration capable of penetrating avertebral body 10 and providing a secure connection. In particular,various configurations contemplated include a hook-shape as shown inFIG. 19, a fin shape as shown in FIGS. 22, 24, 29, an inverted triangle(preferably with the hypotenuse being the distal end portion), a “T”shape, an inverted “L” shape, or a disc-shape.

In one embodiment, as shown in FIG. 1, the piercing portion 180 includesa crook or bent portion 184 intermediate the proximal portion 182 andthe arcuate distal end portion 186. The crook or bent portion 184 allowsfor the piercing portion 180 to have a longer configuration and bepositionable within the central cavity 122 and, as a result, thepiercing portion 180 extends further into the adjacent vertebral body10. As shown in FIGS. 1 and 2, the arcuate end portion 186 extends fromthe crook or bent portion 184 and has a radius of curvature. Preferably,the radius of curvature is such that, when in the securing orientation,the arcuate portion 186 bows away from the upper surface 110 or lowersurface 112 with the end 188 of the piercing portion 180 extendingtoward the upper or lower surface 110 and 112 of the implant body 102.

The crook or bent portion 184 further aids in urging the implant device100 toward the vertebral bodies 10 to produce a firm engagement betweenthe vertebral bodies 10 and one or both of the upper and lower surfaces110, 112. In particular, as the piercing portions 180 rotated into thevertebral bodies 10 the ends 188 extend away from the implant body 102 adistance determined by the length and radius of curvature of the arcuateportions 186 and, after extending that distance, the ends 188 of thepiercing portions 180 rotate back toward the implant body 102. As theends 188 rotate back toward the implant body 102, at least one of thepenetrated vertebral bodies 10 and the implant body 102 is urged towardthe other, or both are urged and shifted toward each other, resulting ina more secure and flush engagement between the implant device 100 andthe vertebral body 102.

The implant device 100 can include a stop mechanism to secure thepiercing portions 180 in the appropriate location within the adjacentvertebral body 10. Preferably, the stop mechanism is configured toeither prevent over-rotation of the piercing portions 180 beyond thedesired location, such as the center support portion or internal wall120. In particular, as the piercing portions 180 are rotated toward thesecuring orientation, the internal wall 120 has an outer surfaceconfigured be abutted against by a base portion 182 of the piercingportion 180 and prevent further rotation of the piercing portion 180.

Alternatively, the stop mechanism can be configured to prevent thepiercing portion 180 from “backing-out” of the vertebral body 10, suchas after the piercing portion 180 has been positioned in the desiredlocation or while the piercing portion 180 is being rotated intoposition, or both. Restricting the rotation of the piercing portions 180after piercing the vertebral body 10 can further prevent micro-fissureswithin the vertebral body 10 and bone growth retardation.

In one embodiment, the stop mechanism 1508 extends from the piercingportion 180. Back-out of the piercing portion 180 is prevented by theinclusion of a sharp projection extending backward obliquely off theforward facing piercing portion 180. In one embodiment, the distal end186 of the piercing portion 180 is configured to include a lockingmechanism such as a hook, barb, or similar configuration which permitsrotation of the piercing portion 180 in one direction but resistsrotation in the opposite direction. For example, the piercing portion180 can include outwardly extending triangular projections along thelength of and on either side of the piercing portion 180.

In an alternative embodiment, the stop mechanism can cause mechanicalinterference to control rotation of the piercing portion 180. The stopmechanism can be configured to provide mechanical interference betweenthe piercing portion 180 and the implant body 102, between the implantbody 102 and the rotatable portion 140, or between the piercing portion180 and the rotatable portion 140. The stop mechanism can be configuredto include a mechanical unlocking mechanism to allow for removal of thepiercing portions 180 from the vertebral body 10 and for the removal ofthe implant device 100 from between the adjacent vertebrae. Examples ofan unlocking mechanism include a button, lever, removable pin, amechanical reversal or any other mechanically actuated mechanismsuitable for such purpose.

As discussed above, the stop mechanism can include an engagement surfaceof the central support portion or internal wall 120. In particular, theengagement surface restricts the piercing portion 180 from over-rotationby being abutted by the piercing portion 180 when the piercing portion180 is rotated toward the desired configuration.

Alternatively, the stop mechanism can include a pin or screw memberinserted into the vertebral body 10 to impede rotation or movement ofthe piercing portion 180 within the vertebral body 10. The pin or screwmember can extend generally parallel to the upper and lower surfaces110, 112 of the implant body. The pin or screw member can be acceptedwithin a corresponding throughbore of the implant device 100.Alternatively, the pin or screw member can be positioned adjacent thepiercing portion 180, such as adjacent the crook or bent portion 184, toimpede movement of the piercing portion 180 within the implant body 102and to impede rotation of the piercing portion 180 out from the implantbody 102.

Other examples of stop mechanism configurations include a ratchet andpawl mechanism, rack and pinion, a mechanically actuated locking pin ora friction or snap fit connection between piercing portion 180 androtatable portion 140, the piercing portion 180 and implant body 102, orthe rotatable portion 140 and implant body 102.

As shown in FIGS. 1-8, a plurality of gripping portions or teeth 118 maybe formed on the upper and lower surfaces 110, 112 of the implant body102 for engaging the adjacent vertebrae. As illustrated in FIGS. 1, 4,5, the gripping portions 118 are defined in the upper and lower surfaces110, 112 by a plurality of generally arcuate channels 119 extendinggenerally perpendicular to the axis 142 of the implant body 102. Asshown, the gripping portions 118 are uni-directional so that they assistin insertion of and resist explantation of the implant body 102.Alternatively, the gripping portions 118 can include individual teeth.Further, in alternative embodiments, the channels 119 can extend in adirection which is not generally perpendicular to the axis 142 or, thechannels 119 can extend in more than one direction.

Preferably, the gripping portions 118 are configured to be urged intoengagement with the vertebral bodies 10 by rotation of the piercingportion 180 into the vertebral bodies 10. As discussed above, as thepiercing portion 180 rotatably penetrates the vertebral body 10. Theimplant body 102 and vertebral body 10 are urged toward each other intofurther engagement, thereby resisting explantation of the implant device100 from between the adjacent vertebrae 10.

As shown in FIG. 7, the upper and lower surfaces 110, 112 of the implantbody 102 are slanted with respect to each other so as to provide agenerally wedge-shaped implant body 102 having a degree of lordosis. Thedegree of lordosis of the implant body 102 preferably corresponds to thenatural lordosis of the lumbar spine. More specifically, the uppersurface 110 has a line of lordosis extending through the upper leadingedge 104 and the upper trailing edge 106 of the implant body 102, andlower surface 112 has a line of lordosis extending through the lowerleading edge 104 and the lower trailing edge 106 of the implant body102, such that the upper and lower surfaces 110, 112 are spaced apart agreater distance at the trailing edge 106 of the implant body 102 thanat the leading edge 104 of the implant body 102, and the implant body102 has a height at the trailing edge 106 that is greater than a heightat the leading edge 104.

Further, the line of lordosis of the upper surface 110 intersects theaxis 142 of the implant body 102 at a first angle. Similarly, the lineof lordosis of the lower surface 112 intersects the axis 142 of theimplant body 102 at a second angle. The first and second angles may haveany suitable size. Preferably, the first and second angles are sized toprovide a degree of lordosis of the implant body 102 that best matchesthe natural lordosis of the spine. In one preferred form, the firstangle is the same size as the second angle.

Alternatively, the upper surface 110 and the lower surface 112 areconfigured to be convex. The convex configuration of the upper surface110 and the lower surface 112 may have any suitable convexity. Theconvexity is preferably selected to provide the best match to thenatural concavity of the vertebral endplates.

Referring next to FIGS. 9-16, an alternative implant device 200 isshown. The following description will focus on the differences betweenthe implant device 100 and the implant device 200, while a repeateddescription of the otherwise similar or identical features is generallyomitted.

As in implant device 100, implant device 200 includes an implant body202, a rotatable portion 240 and piercing portions 280. As shown inFIGS. 9, 10, piercing portions 280 extend in the opposite direction asthe illustrated piercing portions 180. That is, piercing portion 280include a distal end portion 286 which, when arranged in the securingorientation, extends toward the nearest lateral edge 208 rather thanextending toward the lateral edge 208 furthest from the piercingportion, as in implant device 100. As in implant device 100, and asshown in FIGS. 9, 11, implant device 200 preferably includes multiplerotatable portions 240 with at least one piercing portion 280 extendingfrom each of the rotatable portions 240. By having the distal endportion 286 extend through the center portion of the vertebral body 10,which tends to be softer and less dense, and then extend to the outerportion of the vertebral body 10, which tends to be harder and denser,the implant device 200 may be more firmly secured to the vertebral body10.

As shown in FIGS. 9, 11, 16, in order to accommodate the piercingportions 280 of implant device 200 within the central cavity 222, thecentral cavity 222 extends from lateral edge 208 to lateral edge 208,without a central wall or support portion therebetween. In the insertionorientation, the piercing portions 280, as illustrated in FIG. 16,extend across the central cavity 222 such that a central support orwall, as in implant device 100, would impede the piercing portions 280from being positioned within the central cavity 222. However, it iscontemplated that if the implant device 200 included piercing portions280 which extended from only one of the upper and lower surfaces 210 and212, a central portion or internal wall could be included along thesurface opposite the surface from which the piercing portions 208 extendin the securing orientation.

In addition, the implant body 202 can be configured with thethroughbores 246, 248 of the leading and trailing edges 204, 206positioned toward the lateral edges 208 to provide additional space inthe central cavity 222 for the piercing portions 280 to be positionedwhile in the insertion orientation. More particularly, locating thethroughbores 246 and 248 closer to the lateral edges 208 increases thelateral space between the rotatable portions 240 adjacent the uppersurface 210 and the rotatable portions 240 adjacent the lower surface212.

Further, as shown in FIG. 14, the leading edge 206 preferably includes aremovable securing wall portion 260 that extends across the centralcavity 222. The removable securing wall portion 260 is connected to theleading edge 206 and includes annular throughbores 246 corresponding tothe throughbores 248 of the trailing edges for receiving ends of therotating portions 240 therein.

As shown in FIGS. 13 and 14, the leading edge 206 includes securingbosses 261 sized to be received incorresponding securing slots 263 ofthe removable securing wall portion 260. A securing aperture 262 extendsfrom the upper edge of the removable securing wall portion 260, throughthe securing wall portion 260 to the securing slot 263 and from the slot263 through the removable securing wall portion 260 to the lower edge ofthe removable securing wall portion 260. A corresponding securingaperture 265 extends through the securing bosses 261 of the leading edge206. The securing apertures 262 and 265 are configured to accept asecuring member 264, such as a pin, therein to secure the removablesecuring wall portion 260 to the leading edge 206 of the implant body202.

Referring next to FIGS. 17-21, an alternative implant device 300 isshown. The following description will focus on the differences betweenthe implant device 100 and the implant device 300, with a repeateddescription of the otherwise similar or identical features generallyomitted.

In this embodiment, as shown in FIGS. 17 and 19, the implant device 300includes a rotatable portion 340 which, when in the securingorientation, also acts like the central support portion or internal wall120 of implant device 100. In other words, in the implant device 300,the internal wall 340 is rotatable. More particularly, the rotatableportion or wall 340, when in the securing orientation, extends from theupper surface 310 to the lower surface 312 and from the leading edge 304to the trailing edge 306 of the implant device 300. Preferably, therotatable portion or wall 340 includes gripping portions or teeth 318 onthe narrow opposite surfaces 1502 and 1504 thereof corresponding to thegripping portions or teeth 318 of the implant body 102.

As shown in FIGS. 17 and 21, the rotatable portion 340 includes a bodyor wall portion 352 and an elongate securing portion 371. The body orwall portion 352 is configured to be received in the cavity 322 and,when in the implanted or securing orientation, extend from the leadingedge 304 to the trailing edge 306 and between the upper surface 310 andthe lower surface 312 so that the narrow surfaces 1502 and 1504 arearranged as upper and lower toothed surfaces for gripping thecorresponding vertebral bodes 10.

The body or wall portion 352 includes a keyed throughbore 354 extendingalong the length of the body or wall portion 352. The elongate securingportion 371 includes a head portion 372, a slotted portion 373 and aneck portion 377. The head portion 372 includes a tool engagement endportion 344 therein for being engaged by a tool. As shown, the toolengagement portion 344 includes a hexagonal aperture for receiving anend of a tool therein. The slotted portion 373 includes an upper portion374, a lower portion 375 and a slot 376 extending between the lower andupper portions 374 and 375. The slot 376 allows the upper and lowerportions 374 and 375 to be shifted toward one another thereby varyingthe height or size of the slotted portion 373. When the upper and lowerportions 374 and 375 are not shifted toward one another, the slottedportion 373 has a first height 378 configured to correspond to the keyedthroughbore 354 of the body portion 352. The neck portion 377, which isintermediate the head portion 372 and slotted portion 373, includes asecond height 379, the second height 379 being smaller than the firstheight 378.

The throughbore 346 of the trailing edge 306 includes a step 356therein, the step 356 defining an annular throughbore having a stepdiameter 357. The annular throughbore of the step 356 is configured toaccept the neck portion 377 therein and, in particular, to be largerthan the second height 379 of the neck portion 377 and smaller than thehead portion 372 and the first height 378 of the slotted portion 373.

The implant device 300 is assembled by inserting the slotted portion 373of the elongate securing portion 371 through the throughbore 346 of thetrailing edge 306. The upper and lower portions 374 and 375 of theslotted portion 373 are urged together into the slot 376, effectivelyreducing the height 378 of the slotted portion 373 to less than the stepdiameter 357. The body portion or wall 352 is positioned within thecentral cavity 322 of the implant body 302 to receive the slottedportion 373 within the keyed throughbore 354. The elongate securingportion 371 is shifted along the axis 342 until the slotted portion 373is within the throughbore 348 of the leading edge 304, the neck portion377 is disposed within the step 356 of the trailing edge 306, and thehead 372 is disposed within the throughbore 346. The elongated securingportion 371 is thereby secured within the central cavity 322 bothlaterally, as the elongate securing portion 371 extends throughthroughbores 346 and 348 thereby preventing lateral movement, andlongitudinally, as the elongate securing portion 371 is positioned sothat the head portion 372 and slotted portion 373 are on either side ofthe step 356, with both the head portion 372 and slotted portion 373sized larger than the diameter 357 of step 356. The keyed throughbore354 resists compression of the first and second portions 374 and 375toward one another, thereby maintaining the first height 378 of theslotted portion 373. As a result, the size of the head portion 372 andthe height of the slotted portion 373 prevent the elongate securingportion 371 from translating along the axis 342.

The keyed throughbore 354 and elongate securing portion 3721 areconfigured to transmit torque applied by a tool 1000 engaging the toolengagement portion 344 to the body or wall portion 352 of the rotatableportion 340. In particular, the upper and lower portions 374, 375 of theslotted portion 373 are configured to engage the keyed throughbore 354and rotate the body or wall portion 352 as rotational force is appliedto the tool engagement portion 344.

An exemplary piercing portion 380 is shown in FIG. 17, which includes athinner and curved overall configuration. As with implant device 100,the piercing portion 380 can include various configurations based on theapplication and circumstances.

Referring next to FIG. 22, implant device 400, an alternative embodimentof implant device 300, is shown. In particular, implant device 400includes piercing portions 480 having a wedge-shaped configuration. Thepiercing portions 480 include a pointed configuration along a leadingend 482 and distal end 486 for penetrating the vertebral bodies 10. Asthe piercing portions 480 are rotated toward a securing orientation, theentire leading end 482 of each piercing portion engages and penetratesone of the vertebral bodies 10. Referring to FIG. 23, implant device500, an alternative embodiment of implant device 300 is shown. Inparticular, implant device 500 includes multiple piercing portions 580,similar to piercing portions 180, extending from the upper and lowersurfaces 510, 512. The piercing portions 580 each include a flat cuttingedge 582 at a distal end 584 of the piercing portions 580 to penetratethe vertebral bodies 10.

Referring next to FIGS. 49-54, an alternative implant device 1200 isshown. The following description will generally focus on the differencesbetween the implant device 100 and the implant device 1200.

The implant body 1202, as shown in FIGS. 49-53, includes a pair ofspaced center walls 1208 and an outer wall 1400 extending about thespaced center walls 1208. The outer wall 1400 and the spaced centerwalls 1208 provide a spaced pair of cavities 1204 configured to extendbetween adjacent vertebrae 10. The outer wall 1400 includes a leadingedge wall 1206 and a pair of sidewalls 1212 extending from either end1216 of the leading edge wall 1206. The central walls 1208 includeadjacent proximal ends 1402 and 1404 which extend from a generallycentral portion 1210 of the leading edge wall 1206 and adjacent distalends 1214 which connect to trailing ends 1406 and 1408 of the sidewalls1212.

As shown in FIGS. 49-53, the spaced center walls 1208 have a slotopening 1464 therebetween generally rectangular in profile and open atone end to receive an anchoring device 1217 therebetween and closed bythe wall 1206 spanning the center walls 1208 at the other end. Similarto the implants 100 and 200 as shown in FIGS. 1 and 11, the anchoringdevice 1217 includes elongate scissor arms members 1218 configured topivot between an insertion orientation 1220, as shown in FIGS. 49-51,and a securing orientation 1220, as shown in FIGS. 52 and 53. In theinsertion orientation 1220, the scissor arms 1218 are generallypositioned between upper and lower surfaces 1222 and 1224 of the implantbody 1202 and arcuate bone penetrating ends 1234 and 1236 of theopposite end portions 1228 and 1229 generally do not extend beyond theteeth 1246 of the implant device 1200. In the securing orientation 1226the bone penetrating ends 1234 and 1236 of the opposite end portions1228 and 1229 of the scissor arms 1218 extend beyond the implant bodyupper and lower surfaces 1222 and 1224. However, unlike implants 100 and200, the scissor arms 1217 have a scissor configuration such that, asshown in FIGS. 49-53, the scissor arms 1218 can pivot about a singlepivot member 1230 such as a pivot shaft extending between the spacedcentral walls 1208.

The scissor arms 1218 each include an elongate base arm 1410 and 1412with the opposite end portions 1228 and 1229 extending transversely tothe elongate base arms 1410 and 1412, as best seen in FIG. 54. Anaperture 1250 extends through each base arm portion 1410 and 1412 to bealigned with each other for pivotably receiving the pivot pin 1230therethrough. As shown in FIGS. 49-54, the elongate base arm 1410 and1412 and the opposite end portions 1228 and 1229 of the scissor arms1218 have an “S” shaped configuration 1232. As a result, as the scissorarms 1218 shift to the securing configuration 1226 a first bonepenetrating portion 1234 engages one vertebral body 10 and a bonepenetrating portion 1236 engages an adjacent vertebral body 10.

As shown best in FIGS. 49, 52 and 54, the scissor arms 1218 can includea tool engagement portion 1238 extending from one of the opposite ends1228 of the scissor arm 1218 for being directly engaged by an engagementend portion 1416 of a tool 1414, rather than the tool engaging anactuator. In particular, the tool engagement end portion 1238 extendstransversely from the surface of the opposite end portion to provide adefined engagement surface to be engaged by the tool. In one aspect, asshown in FIG. 54, the tool engagement portion 1238 can be a small boss1239 extending from one of the opposite end portions 1228 of the scissorarms 1218; however other configurations, including grooves and pins arecontemplated.

As shown in FIGS. 49 and 51, with the scissor arms 1218 in the insertionorientation 1220, the bosses 1239 extending from one of the opposite endportions 1228 of the scissor arms 1218 are positioned adjacent oneanother to allow both bosses 1239 to be engaged from a single generaldirection. In this manner, both adjacent bosses 1239 can be readilyengaged simultaneously by corresponding engagement end portions 1416 ofa single tool 1414 as by an abutting interface 1466 therebetween. Onceengaged, the tool 1414 can be operated to apply force on the bosses 1239extending from the one opposite end 1228 so that the scissor arms 1218pivot about the pivot pin 1230 extending through the apertures 1250 ofelongate bases 1410 and 1412 of the scissor arms 1218. Each scissor arms1218 is pivoted so that the bone penetrating portion 1234 of the oneopposite end 1228 pivot toward and penetrate one of the adjacentvertebral bodies and the bone penetrating portion 1236 of the otheropposite end 1412 of the scissor arm 1218 pivot toward and penetrate theother adjacent vertebral body. Once the bone penetration portions 1234and 1236 are driven to their securing position in the correspondingvertebral bodies, the tool is easily withdrawn away from the scissorarms 1218 with the engagement end portion 1416 of the tool 1414disengaging the boss 1239 at the end 1228 of the scissor arm 1218without requiring any special disconnection steps for this purpose. Assuch, the engagement end portions 1416 of the tool 1414 are configuredto automatically disengage from abutting engagement with the bosses 1239of the scissor arms 1218 as the tool 1414 is pulled away from theimplant device 1200. As indicated above, both scissor arms 1218 can beengaged and forcefully pivoted about the pivot pin 1230 simultaneouslyor individually.

As shown in FIGS. 49 and 51, the implant device 1200 is configured toprovide access to the tool engagement portions 1238 of the scissor arms1218. In particular, the outer wall 1400 includes a gap opening 1213therein extending between the ends 1214 of the spaced center walls 1208leading to slot opening 1464 between the center walls 1208. The gapopening 1213 allows for the tool 1414 to access the tool engagementportions 1238 of the scissor arms 1218 positioned between the spacedcenter walls 1208. As shown in FIG. 49, the scissor arms 1218 can besized to extend into or beyond the gap opening 1213 with the scissorarms 1218 in the insertion orientation 1220.

As shown in FIG. 51, the pivot pin 1230 can be closer to the adjacentdistal ends 1214 of the center walls 1208 than the opposite ends 1406and 1408 of the center walls 1208. The offset pin 1230 allows for use oflarger scissor arms 1218 sized to extend from the opposite ends 1406 and1408 of the center walls 1208 and into the gap 1213 of the outer wall1400.

As shown in FIG. 54, the inner facing surfaces 1252 of the scissor arms1218 have a flat configuration to provide low friction engagementtherebetween as the scissor arms 1218 are pivoted about the rod 1230.Alternatively, it is contemplated that the facing surfaces 1252 cancooperate with one another, such as via interlocking splines 1462thereof, as shown in FIG. 61, that are configured to permit rotation ofthe scissor arms 1218 toward the securing configuration 1226 and resistmovement of the scissor arms 1218 away from the securing configuration1226.

The implant body 1202 can include a stop portion 1240 to limit therotation of the scissor arms 1218. As shown in FIGS. 49 and 50, theimplant body 1202 can include an upper stop member 1242 and a lower stopmember 1244 extending between the central wall portions 1208 at anintermediate location therebetween to be positioned to be engaged by thescissor arms 1218 as the scissor arms 1218 are being pivoted to thesecuring configuration 1226.

As described above, and similar to implants 100 and 200, the implantdevice 1200 can include features to minimize or mitigate movement of theimplant device 1200 after installation. In particular, similar to theimplant device can include gripping teeth 1246 along the upper and lowersurfaces 1222 and 1224 for engaging the adjacent vertebral bodies 10.Additionally, the scissor 1218 can include a locking mechanism (notshown) to resist migration of the scissor arms 1218 out of the bone ofthe adjacent vertebral bodies 10.

Referring next to FIGS. 55-60, an alternative implant device 1300 isshown. The following description will focus on the differences betweenthe implant device 1200 and the implant device 1300, with a repeateddescription of the otherwise similar or identical features generallyomitted.

The implant body 1302, as shown in FIGS. 55-59, includes a pair ofspaced center walls 1308 and an outer wall 1420 extending about thespaced center walls 1308. The outer wall 1420 and spaced center walls1308 provide a spaced pair of cavities 1304 extending between adjacentvertebrae 10. In contrast to implant device 1200, the outer wallincludes a pair of leading edge walls 1306 and a pair of arcuatesidewalls 1312 extending from outer ends 1316 of the leading edge walls1306. The central walls 1308 include adjacent proximal ends 1422 and1424 which extend from inner ends 1310 of the leading edge walls 1306and adjacent distal ends 1314 connected to trailing ends 1426 and 1428of the sidewalls 1312.

As shown in FIGS. 55-58, and similar to implant device 1200, the implantdevice 1300 includes a gap opening 1313 of the outer wall 1420 betweenadjacent distal ends 1314 of the spaced center walls 1308. In addition,the implant device 1300 includes a second gap opening 1430 of theleading walls 1306 of the outer wall 1420 between adjacent proximal ends1422 and 1424 of the center walls 1308. The gap openings 1313 and 1430provide clearance for oversized arcuate bone penetrating ends 1360 and1361 of the scissor arms 1318 pivotably secured between the center walls1308.

As with implant device 1200, the scissor arms 1318 include an elongatebase arm 1432 with opposite end portions 14 and 1329. As shown in FIG.60, the oversized ends 1360 and 1361 extend from the opposite endportions 1328 and 1329 and transversely to the elongate base arm 1432.As shown in FIG. 60, the scissor arms 1318 have an “S” shapedconfiguration 1332 so that as the scissor arms 1318 shift to a securingconfiguration 1326, a first bone penetrating portion 1334 of one of theoversized ends 1360 engages one vertebral body 10 and a second bonepenetrating portion 1336 of the other oversized end 1361 engages anadjacent vertebral body 10.

The bone penetrating portions 1334 and 1336 of the oversized ends 1360and 1361 of the scissor arms 1318 have a width wider than the width ofthe base portions 1432 of the scissor arms 1318. By increasing the sizeof the bone penetrating ends 1334 and 1336 of the scissor arms 1318, thebone penetrating portions 1334 and 1336 embedded in the adjacentvertebral bodies 10 can overcome larger forces which may try andseparate the implant body 1302 from the surfaces of the vertebral body10. In particular, the increased surface area between bone penetratingportions 1334 and 1336 of the oversized ends 1360 and 1361 and thesurrounding bone materials provides increased resistance to separationforces between the vertebral bodies 10 and the implant device 1300anchored therebetween.

The scissor arms 1318 can be formed as a single piece or can be multiplepieces connected together. In particular, the intersection of theelongate base arms 1432 and the opposite ends 1328 and 1329 includingoversized bone penetrating portions 1334 and 1336 should be constructedto withstand the stress of piercing a vertebral body 10 with theoversized bone penetrating ends 1334 and 1336.

As shown in FIGS. 55-60, and similar to implant device 1200, the centerwalls 1308 are spaced sufficiently so that a slot opening 1460 is sizedto receive the scissor arms 1318 therebetween. The scissor arms 1318 areconfigured to pivot between an insertion configuration 1320, as shown inFIGS. 55-57, and a securing configuration 1326, as shown in FIGS. 58 and59. In the insertion configuration 1326, the bone penetrating portions1334 and 1336 of the scissor arms 1318 are generally positioned betweenupper and lower surfaces 1322 and 1324 of the implant body 1302. In thesecuring configuration 1326, the bone penetrating portions 1334 and 1336of the scissor arms 1318 extend beyond the implant body upper and lowersurfaces 1322 and 1324. As shown in FIG. 60, the elongate base arms 1432of the scissor arms 1318 include a throughbore 1350 for receiving apivot pin or rod 1330 secured to and extending between the spacedcentral walls 1308. The scissor arms 1318 are configured to pivot aboutthe pivot pin 1330 between the central wall portions 1308 from theinsertion configuration 1320 to the securing configuration 1326.

To accommodate the oversized bone penetrating portions 1334 and 1336 ofthe scissor arms 1318 in the insertion orientation 1320, the implantbody 1302 includes cut out portions 1370 and 1372 of the leading edgewall 1306 and side wall 1312 at the intersection of the side wall 1312and the central wall 1308. As best shown in FIGS. 55 and 58, the cutoutportions 1370 and 1372 include curved wall portions 1374 and 1376. Thecurved wall portions 1374 and 1376 are configured to correspond to thecurvature of a curved underside wall 1378 of the oversized bonepenetrating portions 1334 and 1336 to allow for free rotation of thescissor arms 1318 without impedance or interference from the side wall1312 or leading edge walls 1306.

As with implant device 1200, and as shown best in FIGS. 55, 58 and 60,one of the opposite ends 1328 of the scissors 1318 can include a toolengagement portion 1338 for being directly engaged by an engagement end1416 of a tool 1414. By directly engaging the tool engagement portion1338 with the engagement end portion 1416 of the tool 1414 and shiftingthe tool engagement portion 1338 toward the vertebral body 10 thescissor arms 1318 can be pivoted about the pivot pin 1330 from theinsertion configuration 1320 to the securing configuration 1326. As bestshown in FIG. 60, the tool engagement portion 1338 includes a roundedgroove 1339 into which correspondingly configured engagement endportions 1416 of a tool 1414 fit for pivoting one of the scissor arms1318. Other configurations of the tool engagement portion 1338,including a squared-off groove or a protruding boss or pin, are alsocontemplated.

Extending across a generally central area 1319 between the center walls1308 are upper and lower bridge walls 1320 and 1321. The bridge walls1320 and 1321 extend along the upper surface 1323 and lower surface 1325of the implant body 1302. Further, the bridge walls 1320 and 1321 arepositioned and configured to act as a stop member to restrictover-pivoting of the scissor arms 1318.

Referring next to FIGS. 24-28, an alternative implant device 600 isshown. The following description will focus on the differences betweenthe implant device 100 and the implant device 600, with a repeateddescription of the otherwise similar or identical features generallyomitted.

The implant device 600 includes an implant body 602 and piercingportions 680. The configuration of implant body 602 can include anyimplant device or artificial disc which is rotatable between adjacentvertebrae, and particularly the implants described in U.S. PatentApplication Publication No. 2006/0129238 to Paltzer and U.S. PatentApplication Publication No. 2007/0282441 to Stream et al., both of whichare hereby incorporated in their entirety herein.

Generally, the implant body 602 includes a leading end 604, a trailingend 606, a tool engagement portion 616 in the form of opposite sideslots, lateral surfaces 608 into which the slots of the tool engagementportion are formed, an upper surface 610, a lower surface 612 andgripping portions or teeth 618. More particularly, the lateral surfaces608, the upper surface 610 and the lower surface 610 extend between theleading end edge 604 and the trailing end edge 606. Adjacent the leadingend 604, the lateral surfaces 608 extend between the upper and lowersurfaces 610 and 612. However, as shown in FIGS. 24-28, the lateralsurfaces 608 include spaced surface portions positioned adjacent theupper and lower surfaces 610 and 612 and on either side of the toolengagement slot 616. Gripping portions or teeth 618 are formed on theupper and lower surfaces 610 and 612 and extend outwardly therefrom. Asshown in FIG. 24, the tool engagement portion 616 extends from thetrailing end 606 along the lateral surfaces 608 of the implant body 602.

As shown in FIGS. 24-28, the implant body 602 is configured to berotated between the adjacent vertebrae 10 so that the upper and lowersurface 610 and 612 engage the adjacent vertebral bodies 10. In oneembodiment, the implant body 602 does not include a central cavity asfound in implant device 100. In the illustrated embodiment as shown inFIGS. 24-28, the implant body 602 defines a central cavity 622positioned between the leading end 604, trailing end 606 and lateralsurfaces 608 which preferably extends between the upper surface 610 andthe lower surface 612. The implant body 602 also includes an axis 643which is defined by the length 603 of the implant body 602.

As shown in FIGS. 24 and 25, the leading end 604 includes a tapered,contoured surface configured to ease insertion of the implant device 600between adjacent vertebrae.

In one embodiment, the lateral surfaces 608 of the implant body 602 havea convex configuration to ease insertion and rotation of the implantdevice 600 between the adjacent vertebrae. The convex lateral surfaces608 reduce the torque on the tool required to begin rotation of theimplant device 600 between the vertebral bodies 10 toward the securedorientation.

The implant device 600 further includes at least one piercing portion680. Preferably, the implant device includes at least two piercingportions 680, such as shown in FIGS. 24 and 27. As shown in FIGS. 24-28,the implant device 600 includes at least one piercing portion 680extending from the upper surface 610 and at least one piercing portion680 extending from the lower surface 612 to engage each of the adjacentvertebral bodies 10. As best shown in FIGS. 26 and 27, the piercingportions 680 are oriented so they both penetrate the adjacent vertebralbodies 10 as the implant body 602 is rotated in a predetermined rotarydirection, such as clockwise as shown in FIG. 27.

The implant device 600 is configured to be inserted between adjacentvertebra 10 with the lateral surfaces 608 in contact with the vertebralbodies 10, while the upper and lower surfaces 610 and 612 extendingbetween the vertebral bodies 10 and the piercing portions 680 extendingfrom the upper and lower surfaces 610 and 612 are not engaged with thevertebral bodies. The piercing portions 680 are configured to extendbetween the lateral surfaces 608 and away from the upper and lowersurfaces 610 and 612 to provide adequate engagement with the vertebralbodies 10 in the securing orientation to resist separation between theimplant body 602 and the vertebral bodies. Additionally, the piercingportions 680 are sized to not extend beyond the vertebral bodies 10 whenin the insertion orientation between the adjacent vertebrae.

After the implant device 600 is positioned between the adjacentvertebrae, the implant body 602 is engaged by a tool at the toolengagement portion 616 and the entire implant device 600 is rotatedabout the axis 643 so that the piercing portions 680 penetrate theadjacent vertebrae and the upper and lower surfaces 610, 612 are inengagement with the adjacent vertebral bodies 10. More particularly, asthe implant body 602 is rotated about the axis 643, the piercing portion680 and the teeth 618 adjacent a leading edge 691 of the piercingportion 680 engage the vertebral bodies prior to the teeth 618 adjacenta flat end surface 690 opposite the penetrating edge 691. The piercingportions 680 each include a cutting wall portion 682 and a cutting ledgeportion 686. As shown in FIG. 25, the cutting wall portion 682 of thepiercing portion 680 extends generally normal to the axis 643 of theimplant body 602. The cutting ledge portion 686 extends transversely tothe cutting wall portion 686 from a distal end of the cutting wallportion 682. As shown in FIG. 24, the cutting wall portion 682 of eachpiercing portions 680 is connected to one of the upper and lowersurfaces 610 and 612, and extends from one of the lateral surfaces 608,across the central cavity 622 and to the other lateral surface 608. Inone embodiment, as shown in FIG. 24, the cutting wall portion 682includes a rounded lower arc portion 683 extending across the centralcavity 622.

The piercing portion 680 further includes the penetrating leading edge691 of the cutting wall portion 682 extending from one of the lateralsurfaces 608 to the cutting ledge portion 686. Opposite the penetratingleading edge 691 is the flat end surface 690 extending from the otherlateral surface 608 to the cutting ledge portion 686. Additionally, thecutting wall portion 682 includes a pair of opposing sidewall surfaces694 extending the penetrating edge 691 and the flat end surface 690. Thepenetrating edge 691 is configured to ease penetration of the vertebralbody 10 as the implant device 600 is rotated between the adjacentvertebrae. Preferably, the penetrating edge 691 can include a taperedconfiguration 692 as shown in FIG. 27. Further, it is preferable thatthe penetrating edge 691 is configured to ease penetration, such as byhaving a concave configuration 692, as shown in FIG. 27. In a furtherpreferable embodiment, the penetrating edge 691 includes a sharpenededge to facilitate insertion into the vertebral body 10. The flat endsurface 690, as shown in FIGS. 26 and 27, is configured to provide ablunt engagement with the vertebral bodies so that the implant body 602is rotatable toward the securing orientation by rotating the implantbody 602 in a specified direction.

As shown in FIGS. 24, 26, 27, the cutting ledge portion 686 of thepiercing portion 680 includes a shelf 687 configured to resemble anarrowhead and extending generally normal to the penetrating edge 691 andgenerally parallel to the axis 643 of the implant device 600. In oneembodiment, the shelf 687 can extend outwardly toward the leading end604 of the implant body 602. In an alternative embodiment, the shelf 687extends outwardly toward the trailing end 606 of the implant body 600or, as shown in FIG. 25, toward both the leading end 604 and thetrailing end 606. The shelf 687 provides additional engagement with thevertebral bodies and acts to further resist separation of the vertebralbodies and the implant device 600.

Finally, the shelf side 689 may be rounded, flat or tapered. In apreferable embodiment the shelf sides 689 have a convex surfaceconfiguration, as shown in FIGS. 24, 25. In one embodiment, as shown inFIG. 24, the shelf 687 can include a locking mechanism 670 to resistmovement of the shelf 687 after being shifted into the vertebral body10. As shown in FIG. 24, the locking mechanism 670 of the arrow-headshaped shelf 687 can include cutout portions configured to resistmigration or back out of the implant device 600 from between adjacentvertebrae.

Preferably, the piercing portions 680 are configured to be generallyconfined between the lateral surfaces 608 and the leading and trailingends 604 and 606 of the implant body 602, as shown in FIGS. 26 and 27,so as to not engage the vertebral bodies 10 with the implant body 602 inthe insertion orientation.

The piercing portions 680 can be further secured within the vertebralbodies 10 by a securing member 601 as shown in phantom in FIG. 24. Thesecuring member is configured to extend through the vertebral body 10and a securing throughbore 696 of the cutting wall portion 682 of thepiercing portion 680. Preferably, the securing member extends generallyparallel to the axis 643. As shown in FIGS. 26, 27 and discussed above,the securing throughbore 696 extends from one sidewall surface 694 ofthe cutting wall portion 682 of the piercing portion 680 to the othersidewall surface 694, and is generally centrally located intermediatethe flat end surface 690 and the piercing edge 691.

In one embodiment, the piercing portion 680 further includes at leastone small throughbores 697. The small throughbores 697 are preferablylocated adjacent the securing throughbore 696. In one embodiment, thesmall throughbores 697 and securing throughbore 696 each define an axisthat extends parallel to the shelf 687. In a preferred embodiment, thepiercing portion 680 includes at least one small throughbore 697 betweenthe flat end surface 690 and the securing throughbore 696 and at leastone small throughbore 697 between the penetrating edge 691 and thesecuring throughbore 697, as shown in FIGS. 24, 26 and 27.

The small throughbores 697 can be used to house additional, smallersecuring members. Alternatively, the small throughbores 697 can beconfigured to accept radiographic markers therein to assist in insertionof the securing member within the securing throughbore 696.Additionally, the small throughbores 697 can be configured to permitbone growth therethrough, and may be configured to accept bone growthpromoting material therein.

Referring next to FIGS. 29-31, an alternative implant device 700 isshown. The following description will focus on the differences betweenthe implant device 600 and the implant device 700, with a repeateddescription of the otherwise similar or identical features generallyomitted.

The implant device 700, as shown in FIG. 29, includes two piercingportions 780 extending from the upper surface 710 and two piercingportions 780 extending from the lower surface 712. The piercing portions780 include a curved configuration 798 such that the piercing portions780 extend away from the upper and lower surfaces 710 and 712 and towardone of the leading and trailing ends 704 and 706. As shown in FIG. 29,the piercing portions 780 adjacent the leading end 704 extend toward theleading end 704 and the piercing portions 780 adjacent the trailing end706 extend toward the trailing end 706. It is also contemplated that thepiercing portions 780 include a curved configuration 798 and extend inthe same direction from the implant body 702, or, alternatively, thatthe piercing portions 780 would extend toward the central point of theimplant body 702 along the axis 743.

By having at least two piercing portions 780 to extend in differentdirections, the implant device 700 is more secure between the adjacentvertebrae 10 and is able to better resist explantation. The degree ofcurvature of the curved portion 798 is configured to provide a stableinterface between the piercing portion 780 and the vertebral body 10 andto secure the implant device 700 between the adjacent vertebrae.

Additionally, the piercing portion 780 of the implant device 700, asshown in FIGS. 29, 31, includes a piercing edge 791 which is configuredto include a convex configuration 799 to ease insertion into thevertebral body 10. In more detail, by configuring the piercing edge 791so that the vertebral body 10 is first engaged by a small portion of thepiercing edge 791, less torque is required to initially penetrate thevertebral body 10 than if the entire piercing edge 791 engages thevertebral body 10 at once. After the vertebral body 10 is initiallypenetrated, the convex configuration 799 of the piercing edge 791provides for a gradual increase in the amount of the piercing edge 791penetrating the vertebral body until the entire piercing edge 791 isengaging the vertebral body 10.

As best shown in FIGS. 29 and 30, and in contrast to implant device 600,the shelf 787 of each of the piercing portions 780 extends only towardthe closer of the leading edge 704 and trailing end 706, similar to thecurved configuration 798 of the piercing portions 780. Referring next toFIGS. 39-43, an alternative implant device 800 is shown. The followingdescription will focus on the differences between the implant device 800and the implant devices 600 and 700, with a repeated description of theotherwise similar or identical features generally omitted.

As with implant devices 600 and 700, the implant body 802 includes aleading end 804 for being initially inserted between adjacent vertebralbodies 10. A trailing end 806 opposite the leading end 804 includes atool engagement portion 816 for being engaged by an engagement endportion 1416 of a tool 1414 for inserting the implant body 802 betweenthe adjacent vertebrae 10 and rotating the implant body 802 between theadjacent vertebrae 10 from the insertion orientation to the securingorientation. The leading end 804 and trailing end 806 are separated by adistance 803 which defines the longitudinal axis 843 of the implant body802.

A pair of lateral surface 808 extends between the leading end 804 andtrailing end 806 and each include a generally smooth surface 807 whichface the vertebral bodies 10 during insertion with the implant body 802in the insertion orientation. The smooth surface 807 of the lateraledges 808 provides low friction engagement when shifting the implantbody 802 between the vertebral bodies 10 during insertion and minimizesany abrasion or alteration of the surface of the vertebral bodies 10 bythe implant body 802. As shown in FIGS. 39-43, the tool engagementportions 816 include slots formed in the lateral surfaces 808 of theimplant body 802.

An upper surface 810 and opposing lower surface 812 extend between thelateral surfaces 808 and between the leading end 804 and trailing end806. The upper and lower surfaces 810 and 812 include gripping portionsor teeth 818 for engaging the vertebral bodies 10 after the implant body802 has been shifted to the securing orientation.

As shown in FIGS. 39-43, the implant device 800 includes four piercingor anchoring portions 880 extending from each of the upper surface 810and lower surface 812 of the implant body. As shown in FIG. 39, theanchoring portions 880 are fins 881. As with the implant device 700, thefins 881 include a curved configuration 883 such that the piercingportions 880 extend outwardly from the upper or lower surface 810 and812 and toward one of the leading end 804 and trailing end 806 of theimplant body 802. As shown in FIGS. 39-43, the implant body 802 includespiercing portions 880 positioned adjacent the trailing end 806 and theleading end 804, with the piercing portions 880 positioned adjacent theleading end 804 curved toward the leading end 804 and away from thepiercing portions 880 positioned adjacent the trailing end 806.Similarly, the piercing portions 880 positioned adjacent the trailingend 806 are curved toward the trailing end 806 and away from thepiercing portions 880 positioned adjacent the leading end 804. As can beseen in FIG. 39, the distal end 886 of the fins 881 each include arounded edge portion 887, rather than a shelf as with implant devices600 and 700, to reduce the overall size of the fins 881 as the fins 881penetrate the vertebral bodies 10.

As shown in FIGS. 39-43, similar to implants 600 and 700, each fin 881includes a tapered leading edge 888 for initially penetrating avertebral body as the implant device 800 is rotated in a first directionabout the longitudinal axis 8433. Opposite the tapered edge 888, thefins 881 include a flat surface 889 for resisting rotation of theimplant device 800 in a second direction opposite the first direction.

As shown in FIGS. 42 and 43, and similar to implants 600 and 700, thefins 881 each include a securing throughbore 896 for receiving asecuring member therein for further resisting rotation of the implantdevice 800 after the fins 881 penetrate the adjacent vertebral bodies10. Exemplary securing members include pedicle screws, which pierce thevertebral body 10 and extend generally parallel to the face of thevertebral body 10. Further, as shown in FIGS. 42 and 43, the fins 881each include two smaller throughbores 897 on either side of the securingthroughbore 896. The smaller throughbores 897 can be configured toreceive material therein, such as securing members, radiological markersor bone graft material.

Additionally, as with implant devices 600 and 700, the fins 881 areconfigured to be generally confined between the lateral edges 808 of theimplant body 802 so as to minimize any contact between the fins 881 andthe adjacent vertebral bodies 10 during initial insertion of the implantdevice 800 prior to rotation. More particularly, the fins 881 aregenerally confined between the lateral surfaces 808 and the leading andtrailing ends 804 and 806 so that, in the insertion orientation, thefins 881 do not engage the adjacent vertebral bodies 10.

Similar to implants 600 and 700, the teeth 818 of the implant body 802includes two rows of gripping teeth 819 and 821 spaced from one anotherby a central cavity 822. As with implants 600 and 700, the fins 881 spanacross the central cavity 822.

As with implant device 700, as the implant body 802 is rotated betweenthe vertebral bodies 10, a first set of teeth 819 and the fins 881 willinitially engage the vertebral surface. Depending on the configurationof the fins 881, the first set of teeth 819 and the fins 881 may engagethe vertebral body 10 simultaneously or one may engage the vertebralbody before the other. As the implant body 802 is rotated, the teeth 819frictionally engage the vertebral bodies 10 to resist lateral movementof the implant device 800 while the fins 881 penetrate the vertebralbodies 10 to secure the implant device 800 in place. The implant body802 is rotated until the second set of teeth 821 frictionally engagesthe vertebral body to further resist movement of the implant device 800.

Further, as with implants 600 and 700, implant 800 can include a solidimplant body 802 which does not include a cavity.

Referring next to FIGS. 44-48, an alternative implant device 900 isshown. The following description will focus on the differences betweenthe implant device 900 and the implant devices 600, 700 and 800, with arepeated description of the otherwise similar or identical featuresgenerally omitted.

As shown in FIGS. 44-48, the implant device 902 includes a taperedleading end surface 904 for initially being inserted between adjacentvertebral bodies. A trailing end opposite the leading end surface 904includes a tool engagement portion or opposite side slots 916 for beingengaged by an engagement end portion 1416 of a tool 1414 for insertingthe implant body 902 between adjacent vertebrae in an insertionorientation, as shown in FIG. 63, and rotating the implant body 902between the adjacent vertebrae to a secured orientation as shown in FIG.66. A longitudinal axis 943 of the implant body 902 extends between andthrough the leading end surface 904 and trailing end 906.

Smooth, outwardly facing sidewall surfaces 908 and 909 extend betweenthe leading surface 904 and the trailing end 906 and each includeportions raised on either side of the respective tool engagement slots916. The sidewall surfaces 908 and 909 provide low friction engagementwith the vertebral bodies 10 with the implant body 902 in the insertionorientation so that the implant body 902 can be slid to a predeterminedlocation. The sidewall surfaces 908 and 909 are spaced from one anothera distance R to define the width of the implant device 902. The distanceR is selected so that the implant body 902 can be slid between thevertebral bodies 10 in the insertion orientation and has sufficientstructural strength to maintain separation of the vertebral bodies 10 inthe secured orientation. As shown in FIGS. 47 and 48 the sidewallsurfaces 908 and 909 are convex to aid in rotating the implant device900 between the adjacent vertebral bodies 10 to the secured orientation.

Upper and lower surfaces 910 and 912 of the implant body 902 extendbetween the sidewall surfaces 908 and 909, and the leading end surface904 and the trailing end 906. As shown in FIG. 44, the implant body 902can include a central cavity 922 extending between the upper and lowersurfaces 910 and 912 for receiving bone growth material therein; howeverit is contemplated that the implant body 902 can be a solid memberwithout a central cavity 922.

As shown in FIGS. 44-48, the upper and lower surfaces 910 and 912 eachinclude portions 910 a and 910 b and 912 a and 912 b on either side ofthe cavity 922. The upper and lower surfaces 910 a, 910 b and 912 a, 912b are configured to engage the vertebral bodies 10 with the implantdevice 900 rotated to the securing orientation. Gripping members 918,such as teeth, are formed on the upper and lower surfaces 910 and 912and provide frictional engagement with the vertebral bodies 10 to resistmovement of the implant device 10 relative to the vertebral bodies 10with the implant device 900 in the securing orientation.

The gripping portions 918 of the implant body 902 includes spaced firstand second sets of aligned teeth 1450 and 1452 of the upper surface 910a and 910 b and spaced first and second sets of aligned teeth 1454 and1456 of the lower surface 912 a and 912 b. As shown on FIGS. 47 and 48,the spaced sets of teeth 1450 and 1452 of the upper surface 910 a, 910 band the spaced sets of teeth 1454 and 1456 of the lower surface 912 a,912 b are separated by the central cavity 922.

As shown in FIGS. 44-48, the implant device 900 includes anchoringmembers 980 and 981 connected to the implant body 902. In particular, asbest seen in FIGS. 47 and 48, the anchoring members 980 and 981 includebase portions 982 and 983 connected to the implant body 902 andextending beyond the teeth 918 generally orthogonal to the longitudinalaxis 943 of the implant body 902. In particular, the base portions 982of anchoring members 980 extend upwardly beyond the upper surface 910and are connected adjacent the first set of teeth 1450, and as shown inFIGS. 47 and 48, extend from sidewall surface 908. Similarly, the baseportions 983 of anchoring members 981 extend downwardly beyond the lowersurface 912 and are connected adjacent the set of teeth 1454 and extendfrom sidewall surface 909.

The anchoring members 980 and 981 further each include a bonepenetrating portion 986 and 987 extending transversely from the baseportions 982 and 983. As shown in FIGS. 47 and 48, the transition fromthe base portions 982 and 983 to the bone penetrating portions 986 and987 includes a curved configuration 984. The bone penetrating portions986 and 987 include a tapered distal end portion 988 having a sharp orpointed tip end for penetrating the vertebral body 10 as the implantdevice 900 is rotated. Optionally, the bone penetrating portions 980 and981 can include anti-back-out mechanisms, such as a barb or hook toresist movement of the bone penetrating portions 980 and 981 out fromwithin the penetrated vertebral bodies 10.

The bone penetrating portions 986 and 987 are sized to extend across theimplant body toward the sidewall surface 908 and 909 opposite thesidewall surface 908 or 909 to which the base portion 982 and 983 areattached. The bone penetrating portions, in particular, are sized to notextend to the opposite sidewall surface 908 and 909. As shown in FIGS.47 and 48, the bone penetrating portions 986 and 987 extend beyond theteeth 1450 and 1454 adjacent the base portions 982 and 983 and to apoint over the cavity 922, the bone penetrating portions 982 and 983 donot extend to the second sets of teeth 1452 and 1456 opposite the firstsets of teeth 1450 and 1454. While it is contemplated that the bonepenetrating portions 986 and 987 could extend to the second sets ofteeth 1452 and 1456, the bone penetrating portions 986 and 987 do notextend to the sidewall surface 908 and 909 adjacent the second sets ofteeth 1452 and 1456.

As indicated above and as shown in FIG. 63, the implant device 900 isinserted between adjacent vertebral bodies 10 with the sidewall surfaces908 and 909 engaging the vertebral bodies 10. Once the implant device isin the desired location, the implant device 900 can be rotated by thetool 1414 about the longitudinal axis 943 of the implant body 902. Asthe implant device 900 is rotated the second sets of teeth 1452 and 1456of the upper and lower surfaces 910 and 912 engage the vertebral bodiesto provide frictional engagement therewith so that the implant device900 maintains the desired position, as shown in FIG. 64. The implantdevice 900 is further rotated, with the second sets of teeth 1452 and1456 acting to maintain the general position of the implant device 900,as the bone penetrating ends 986 and 987 penetrate the vertebral bodies10, as shown in FIG. 65. More particularly, the second sets of teeth1452 and 1456 bit into the endplate surface while the bone penetratingmembers 986 and 987 of the anchor members 980 and 981 penetrate thevertebral bodies. The teeth 1452 and 1456 provide the frictionalengagement and purchase for the higher torque required on the tool todrive the anchoring members 980 and 981 to penetrate the vertebralbodies 10. The implant device 900 continues to rotate until the firstset of teeth 1450 and 1454 adjacent the base portions 982 and 983 of theanchoring members 980 and 981 engage the vertebral bodies, as shown inFIG. 66.

The base portions 982 and 983 are configured to extend a distance 993from the respective upper and lower surfaces 908 and 910 to allow asufficient amount of the vertebral body 10 to be positioned between theupper and lower surfaces 908 and 910 and bone penetrating members 986and 987 of the anchoring member 980 and 981 to maintain structuralintegrity and strength of the bone therebetween. Further, the baseportions 982 and 983 are sized so that, with the implant body 902 in theinsertion orientation, the anchor members 980 and 981 do not over hangthe edges of the vertebral bodies 10 or otherwise obstruct insertionbetween the vertebral bodies 10.

Referring to FIG. 62, an alternative implant device 1500 is shown. Thefollowing description will focus on the differences between the implantdevice 1500 and the implant devices 600 and 1200.

Similar to implant device 1200, the implant device 1500 includes animplant body 1502 having an outer wall 1504. The outer wall includes aleading edge wall 1506 for being initially inserted between adjacentvertebrae. As shown in FIG. 62, the leading edge wall 1506 includes atapered configuration, similar to implant device 600. Sidewalls 1508extend from the leading edge wall 1506 and include adjacent distal ends1510. The outer wall includes a gap 1512 therein between the distal ends1510 of the sidewalls 1508.

Similar to implant device 600, outwardly facing surfaces 1514 of thesidewalls 1508 have a smooth configuration to provide low frictionengagement with the vertebral bodies as the implant body 1502 isinserted therebetween. Once in place, the implant body 1502 can berotated so that upper and lower surfaces 1516 and 1518 of the implantbody 1502 engage the vertebral bodies. To aid in rotation, the sidewalls1508 can have a convex configuration 1520 and include a tool engagementportion 1522 at the distal ends 1510 thereof to be engaged by anengagement end portion 1416 of a tool 1414.

The upper and lower surfaces 1516 and 1518, as shown in FIG. 62, includegripping portions 1524, such as teeth, formed thereon for providingfrictional engagement with the vertebral bodies and resisting movementof the implant body 1502 relative to the vertebral bodies 10.

To further secure the implant body 1502 in place, the implant device1500 includes scissor arms 1526 and 1528 pivotably connected thereto,similar to implant device 1200. The scissor arms 1526 and 1528 includeelongate base arm portions 1530 having an aperture 1532 therein. Thesidewalls 1508 include corresponding apertures 1534 sized to receive apivot pin 1536 therebetween. The apertures 1532 of the base arm portions1530 are sized to pivotably receive the pivot pin 1536 therethrough sothat the scissor arms 1526 and 1528 can pivot from an insertionorientation to a secured orientation, similar to implant device 1200.

Generally, as shown in FIG. 62, the scissor arms 1526 and 1528 aresimilar to and operate the same as the scissor arms 1218 and 1318 ofimplant device 1200 and 1300.

An alternative implant device 1100 is shown in FIGS. 34-38B. As shown,the implant device 1100 can be used as an anchor for any other type ofdevice requiring a static structure to be mounted on. For example, it iscontemplated that the implant shown in FIG. 34 be used as a blocker toprevent an implant, such as an artificial nucleus implant from escapingfrom a predetermined position between the vertebrae. Alternatively, theimplant device 1100 can be used to plug an opening in an annulus betweenthe vertebral bodies 10. In this embodiment, the blocker is acting as ananchor for the implantation of any other type of artificial nucleus (notshown).

In the blocker embodiment shown in FIG. 35, the implant body 1102 actsas a blocking structure while the mechanically deployable rotatableanchoring members or projections 1180, in the form of hooks, are used tostatically secure the implant device 1100 within bone. The device forsecuring an implant to bone can be seen with the mechanically deployableprojections 1180 deployed in FIGS. 34, 35, 36A, 37A and 38A and with themechanically deployable projections retracted in FIGS. 36, 37 and 38.The implant device 1100 can includes gripping surfaces along one or bothof the upper and lower surfaces 1110 and 1112 to grip the bone andresist movement of migration of the implant device 1100. Alternatively,as shown in FIGS. 34-38, the implant device 1100 can include a smooth,continuous upper surface 1110 to minimize friction between the uppersurface 1110 and adjacent vertebral body 10.

The projections 1180 curve so that they are generally completelyreceived within a recess 1103 extending into the lower surface 1112 ofthe body 1102 in the insertion orientation. The projections 1180 areconnected to a rotatable shaft 1120 which is pivotably connected to theimplant body 1102. The shaft 1120 includes a head portion 1124 having atool engagement portion 1126 for being engaged by a tool. As the toolengagement portion 1126 is engaged and rotated by a tool, the shaft 1120and projections 1180 rotate so that distal ends 1128 of the rotatableprojections 1180 extend out from within the recess 1103 and engage andpenetrate the bone in a securing orientation. Locking mechanisms (notshown), such as described above, can be used to resist migration of therotatable portions 1180 from within the bone.

Preferably, the projections 1180 include an arcuate portion 1181 havinga substantially constant radius of curvature. The radius of curvature isconfigured to correspond to an arc of the circular path traveled by thearcuate portion 1181 as the anchoring member 1180 is pivoted.

The implant devices of the present invention may be fabricated from anysuitable materials having desirable strength and biocompatibility.Suitable materials may include, for example, biocompatible metals andrelated alloys (such as titanium and stainless steel), shape memorymetals (such as Nitinol), biocompatible polymers (including, forexample, materials of the polyaryletherketone family such as PEEK(polyetheretherketone), PAEK (polyaryletherketone), PEK(polyetherketone), PEKK (polyetherketoneketone), PEKEKK(polyetherketoneetherketoneketone), PEEKK (polyetheretherketoneketone),and PAEEK (polyaryletheretherketone), filled materials (such as carbonor glass fiber-reinforced materials), bone substitute materials (such ashydroxyapatite and tricalcium phosphate), composite materials, and/orany combination of the above.

In one preferred form, the implant devices are formed of a PEEK-typematerial. In another from, the implant device may be formed, in whole orin part, or coated with a calcium phosphate ceramic bone substitute suchas hydroxyapatite, tricalcium phosphate, and/or mixtures thereof.Particularly preferred hydroxyapatite and tricalcium phosphatecompositions include those disclosed in, for example, U.S. Pat. No.6,013,591, U.S. Pat. No. RE 39,196, and U.S. Patent ApplicationPublication No. 2005/0031704, which are hereby incorporated in theirentirety herein. Coating with the calcium phosphate ceramics can beachieved by any known method, including dip coating-sintering, immersioncoating, electrophoretic deposition, hot isostatic pressing, solutiondeposition, ion-beam sputter coating and dynamic mixing, thermalspraying techniques such as plasma spraying, flame spraying andhigh-velocity oxy-fuel combustion spraying. In one preferred embodiment,hydroxyapetite coating is achieved by plasma spraying.

In yet another form, the implant device may be formed of a PEEK-typematerial and coated with such a bone substitute material. In yet anotherform, the implant device may be formed, in whole or in part, coatedwith, injected with, incorporate, and/or retain a bone growthstimulating composition such as the bioactive hydrogel matrix described,for example, in U.S. Pat. No. 6,231,881, U.S. Pat. No. 6,730,315, U.S.Pat. No. 6,315,994, U.S. Pat. No. 6,713,079, U.S. Pat. No. 6,261,587,U.S. Pat. No. 5,824,331, U.S. Pat. No. 6,068,974, U.S. Pat. No.6,352,707, U.S. Pat. No. 6,270,977, U.S. Pat. No. 5,614,205, U.S. Pat.No. 6,790,455, U.S. Pat. No. 5,922,339, and U.S. Patent ApplicationPublication No. 2005/0118230, which are hereby incorporated in theirentirety herein.

Alternatively, the implant device of the invention may be formed of twodistinct materials. In particular, the implant body may be formed of afirst material, such as PEEK or carbon fiber PEEK, and the piercingportions may be made of a metal, such as Ti64. In one example, thepiercing portions of implant device 600, 700, and 800 and 900 may beformed of a metal. Additionally, the part or the entire rotatableportion of the implant devices 100, 200, 300, 400, 500, 1100, 1200, 1300and 1500 may be formed of a material distinct from the material used toform the implant body.

The central cavities 122, 222, 322, 422, 522, 622, 722, 822, 922, 1204and 1304 provide a region for receiving bone growth material therein. Inone embodiment, the implant device 100, 200, 300, 400, 500, 600, 700,800, 900, 1100, 1200 and 1300 is packed with bone growth filler prior toimplantation. In a preferred embodiment, the implant device 100, 200,300, 400, 500, 600, 700, 800, 900, 1100, 1200 and 1300 can be implantedin the vertebral space and then packed with bone growth filler.Preferably, the bone growth material is inserted through the insertiontool engagement portion 416. In an alternative preferred embodiment, abioresorbable sponge fixated to the implant device is used to secure thebone growth stimulating composition.

The bone void filler or graft material is preferably a combination ofone or more various substances consisting of bone matrix, bone voidfiller, bone graft extender, biopolymers that stimulate bone growth,bone growth stimulating orthobiologic products, bioactive hydrogelmatrix comprising a polypeptide and a long chain carbohydrate, andosteoinductive or osteoconductive materials, medicaments, stem orprogenitor cells, and three-dimensional structural frameworks. In someembodiments, the bone matter may be a composition made fromde-mineralized bone matrix.

In one embodiment, the bone growth stimulating composition comprises abioactive hydrogel matrix comprising a polypeptide, such as gelatin, anda long chain carbohydrate, such as dextran, such as described in U.S.Pat. No. 6,231,881 to Usala et al. and U.S. Patent ApplicationPublication No. 2005/0118230 to Hill et al., which are incorporated byreference in their entirety herein. In an alternative embodiment, thisbone growth stimulating composition can be integrated withhydroxyapetite or other bone substitutes to provide sustained deliveryof the bone growth stimulating compositions.

In one embodiment, the bone void fillers include a moldable puttyoptimized for implantation which provide significantly greater set timethan most bone void fillers, such as one or both of TrioMatrix™ andFortrOss™. The increased set time allows the bone void filler, in theform of moldable putty optimized for implantation, to be extruded intothe central cavity as the bone void filler remains “moldable” for asufficient length of time. Furthermore, TrioMatrix™ and FortrOss™ havesuperior biological performance for inducing bone growth making themideal as bone void fillers.

The bone void filler, such as TrioMatrix™, is preferably made fromsynthetically made hydroxyapatite, synthetically made gelatin carrier,demineralized bone matrix, and the patient's own blood products and/orbone marrow extract. In another form, the bone void filler, such asFortrOss™, is made from the mixing of synthetically made hydroxyapatite,synthetically made gelatin carrier, and the patient's own blood productsand/or bone marrow extract.

The implant devices can readily be filled with such a moldable bone voidfilling putty. Moreover, biologic materials may be introduced to thisadmixture by the surgeon in the operating room, such as bonemorphogenetic proteins (BMP) or bone growth stimulating compositions, tofurther induce bone growth. In yet another embodiment, bone chips fromthe patient can be added to the bone void filler.

Preferably, the bone void filler composition, such as FortrOss™, is madeof synthetic and autograph materials to eliminate the risk of infectionfrom bone donors and reduce the risk of rejection of the bone filler bythe patient's immune system. Autograft materials are tissue that istransplanted from one portion of the patient's body to another. In theinstant invention, bio-compatible autograft materials from the patient'sown body in the form of blood products or bone chips with syntheticextenders of the autograft material are to be placed in the centralcavity that encourage bone growth within and around the device.

Hydroxyapatite (HA) and tricalcium phosphate (TCP) can be used in thebone void filler for facilitating bone fusion. These compositionsfacilitate fusion by having the characteristic of being “bioactive”which indicates the ability to facilitate a cellular or tissue response,such as, induction of vasculogenesis, promotion of cellular attachmentto a scaffold material, and promotion of tissue regeneration.

The previously described devices for securing an implant to bone willneed to be implanted into the human body. An exemplary tool 1414, asshown in FIG. 49, includes an engagement end portion 1416 for engagingan implant device. A preferred embodiment of a tool apparatus 1000 forimplanting a device for securing an implant to bone is shown in FIG. 33.The apparatus 1000 for implanting the device has a cannulated main shaft1010 with a mechanism 1012 located on the distal end 1014 for attachingan implantable device. The distal end 1014 of the main shaft 1010attaches to the device for securing an implant to bone to allow forminimally invasive surgery from various approaches through the patientsbody.

The main shaft 1010 has a rotatable rod 1016 located with the main shaft1010 capable of longitudinal motion within the main shaft 1010. Therotatable rod 1016 allows the piercing portions to be locked into place.The longitudinal motion of the rod 1016 allows for disengagement of theapparatus 1000 from the device.

In addition, an arm 1020 with a counter-force plate 1022 located on thedistal end 1014 for securing an implant on the main shaft 1010 isprovided as shown in FIG. 33. The counter-force plate 1022 maintainsattachment of the device during the insertion of the device into thepatient. The plate 1022 is disengaged by compressing a spring 1024located between the main shaft 1010 and the arm 1020. The main shaft1010 and the arm 1020 are connected by a pin 1026 that allows the arm1020 to hinge on the main shaft 1010.

The complete method for operating the device for securing an implant tobone begins with making a surgical incision, distracting the tissue inplace, and removing the severely damage tissue. The device is theninserted and positioned in the patient. The rotatable portion is thenrotated, along with the piercing portions, so that the piercing portionspenetrate the adjacent vertebral bodies. The patient is then closed andthe procedure is complete. The bone growth stimulating compounds, theother bone substitutes material, and the patients own body then healsthe remaining wounds and causes the implanted device and adjacent boneto fuse into a solid structure to support the patient's body weight.

Those skilled in the art will recognize that a wide variety ofmodifications, alterations, and combinations can be made with respect tothe above described embodiments without departing from the spirit andscope of the invention, and that such modifications, alterations, andcombinations, are to be viewed as being within the scope of theinvention.

What is claimed is:
 1. A spinal implant for securing adjacent vertebrae,the spinal implant comprising: an implant body for being implantedbetween adjacent vertebral bodies; a plurality of teeth extending fromthe implant body and configured to provide frictional engagement withsurfaces of the adjacent vertebra; a pair of elongate scissor arms;opposite end portions of each of the scissors arms having a bonepenetrating end configured to pierce the surface of the adjacentvertebrae; and a single pivot member distinct from the pair of elongatescissor arms, pivotably interconnecting the pair of scissor armsintermediate the opposite end portions thereof, and being connected tothe implant body such that the scissor arms have an insertionorientation in which the bone penetrating ends of the scissor arms donot extend beyond the plurality of teeth and an anchoring orientation inwhich the scissor arms are pivoted about a single pivot axis defined bythe single pivot member so that the bone penetration ends extend beyondthe teeth of the implant body and pierce the adjacent vertebral bodiesto be embedded therein for anchoring the implant body thereto.
 2. Thespinal implant of claim 1 wherein the scissor arms each include anelongate base arm portion with the opposite end portions extendingtransversely thereto; and an aperture extending through the base armportion for pivotably receiving the single pivot member therethrough. 3.The spinal implant of claim 1 wherein the scissor arms are arranged sothat one of the opposite end portions of one of the pair of scissor armsis adjacent one of the opposite end portions of the other scissor armwith the scissor arms in the insertion orientation, and the adjacent endportions each include a tool engagement portion for being directlyengaged by a tool for pivoting the scissor arms about the single pivotmember so that both bone penetrating ends of each scissor arm piercesthe adjacent vertebral bodies.
 4. The spinal implant of claim 1 whereinthe implant body includes a pair of center walls spaced to receive thescissor arms therebetween with the single pivot member mounted to thecenter walls, and an outer wall extending about and connected toopposite ends of each of the spaced center walls to provide implant bodycavities for receiving bone growth material therein; and a gap in theouter wall extending between adjacent spaced ends of the spaced centerwalls with the elongate scissor arms sized to extend into the gap. 5.The spinal implant of claim 4 wherein the outer wall extends betweenends of the spaced center walls opposite the adjacent spaced endsthereof, and the single pivot member is closer to the adjacent spacedends of the center walls than the opposite ends.
 6. The spinal implantof claim 4 wherein the outer wall has a gap therein between ends of thespaced center walls opposite the adjacent spaced ends.
 7. The spinalimplant of claim 1 wherein the implant body includes opposite smoothsurface portions and opposite gripping surface portions including theteeth thereon with the implant body arranged so that during insertionthe opposite smooth surface portions provide low-friction engagementwith the surfaces of the adjacent vertebral bodies and after rotation ofthe implant body between the adjacent vertebral bodies the teeth of thegripping surface portions frictionally engage the surfaces of theadjacent vertebral bodies.
 8. The spinal implant of claim 1 wherein thescissor arms include engaging splines formed on facing surfaces of thescissor arms to resist pivoting of the scissor arms from the anchoringorientation toward the insertion orientation.
 9. A method for securingan implant device between adjacent vertebral bodies, the methodcomprising: positioning an implant body between adjacent vertebralbodies; engaging a first end portion of an elongate scissor arm with anengagement end portion of a tool; applying force on the first endportion of the elongate scissor arm with the engagement end portion ofthe tool so that the scissor arm pivots about a central pivot of thescissor arm mounted to the implant body so that a first bone penetratingportion of the first end portion penetrates one of the adjacentvertebral bodies and a second bone penetrating portion of a second endportion of the scissor arm opposite the first end portion penetrates theother adjacent vertebral body with the first end portion and the secondend portion being spaced from the central pivot that is disposedcentrally therebetween such that the tool does not apply force centrallybetween the scissor arm end portions; and disengaging the engagement endportion of the tool from the first end portion of the elongate scissorarm.
 10. The method of claim 9 wherein applying force on the first endportion of the scissor arm with the engagement end portion of the toolincludes shifting the first end portion of the scissor arm and theengagement end portion of the tool engaged therewith toward one of theadjacent vertebral bodies.
 11. A method for securing an implant devicebetween adjacent vertebral bodies, the method comprising: positioning animplant body between adjacent vertebral bodies; engaging a first endportion of an elongate scissor arm with an engagement end portion of atool; applying force on the first end portion of the elongate scissorarm with the engagement end portion of the tool so that the scissor armpivots about a central pivot mounted to the implant body so that a firstbone penetrating portion of the first end portion penetrates one of theadjacent vertebral bodies and a second bone penetrating portion of asecond end portion of the scissor arm opposite the first end portionpenetrates the other adjacent vertebral body; disengaging the engagementend portion of the tool from the first end portion of the elongatescissor arm; engaging a first end portion of a second elongate scissorarm adjacent the first end portion of the elongate scissor arm with theelongate scissor arm and second elongate scissor arm in the insertionorientation with a second engagement end of the tool; applying force onthe first end portion of the second elongate scissor arm with the secondengagement end of the tool so that the second scissor arm pivots in adirection opposite the first scissor arm about the central pivot mountedto the implant body so that a first bone penetrating portion of thefirst end portion of the second scissor arm penetrates the otheradjacent vertebral body and a second bone penetrating portion of asecond end portion of the second scissor arm opposite the first endportion of the second scissor arm penetrates the one adjacent vertebralbody; and disengaging the second engagement end of the tool from thefirst end portion of the second elongate scissor arm.
 12. The method ofclaim 11 wherein the force is applied simultaneously to the first endportion of the first scissor arm and the first end portion of the secondscissor arm.
 13. The method of claim 9 wherein disengaging theengagement end portion of the tool from the first end portion of thescissor arm only requires pulling the engagement end portion of the toolengaged with the first end portion of the scissor arm away from thescissor arm.
 14. The method of claim 9 wherein positioning the implantbody includes rotating the implant body positioned between the adjacentvertebral bodies so that opposing gripping surfaces of the implant bodyhaving teeth extending therefrom engage the adjacent vertebral bodiesprior to engaging the first end portion of the elongate scissor arm withthe engagement end portion of the tool.